“When he was using marijuana as a teen I would have never dreamed he would have touched heroin,” Joyce said.

Josh’s parents, and his sister, Lauren, started noticing changes in his mood after graduation as he transitioned from high schooler to adult. Lauren, who is three years older than her late brother, now wants to be an addiction counselor.

“I’m from a pretty normal family in my opinion. My parents are well educated and were here for me and our brothers. It can happen to any family,” she said.

Family members say they tried everything. Josh had been in rehab three times this year, the last time in August just weeks before his death, and was set to go back five days after he died.

“I saw him Tuesday night, the night before he passed away. He said he was going to turn his life around, enter a long-term program,” Rick said.

Then came the sheriff’s knock on the door: Josh had overdosed while staying with a friend he’d met in treatment.

“People going into treatment need to know that. Don’t use ‘one more time,'” the father said.

Now the Isaacs visit Josh’s Westlake Village grave, rather than a college dorm, plagued by thoughts of how they could have prevented his death.

“It’s hard for a parent because when they’re little, you can fix stuff. Then they grow up and they’re the only ones that can fix it,” Joyce said.

The family has created a foundation in Josh’s name, hoping to boost awareness about teen heroin addiction and build a dialogue.

“There’s this denial that goes on — ‘I know personally that nothing like that could happen to my kid, never,'” Joyce said.

According to the Los Angeles Overdose Prevention Center, overdose deaths have doubled since 1990. They’re now the second-leading cause of accidental deaths in California for people 15 to 34 years old, second only to traffic accidents.

“I know it’s a serious problem here. There is no discussion. There is a big heroin problem in Agoura/Calabasas. The kids need that fear of drugs when I grew up. They need a fear of it,” Joyce said.

Recent studies suggest there is a shift from injecting heroin — to snorting or smoking it — because of increased purity, and the misconception that these forms won’t lead to addiction. Experts say it’s pure, abundant, and as cheap as a movie ticket.

Cartels are bringing much of it from south of the border, and law enforcement in the greater Los Angeles communities of Agoura, Simi Valley, Santa Clarita and La Cresenta say it’s a growing problem. Narcotics detectives say dealers hook teens by giving them their first few hits for free.

The Isaacs say they’re aware of two other teens who’ve nearly died from overdosing since Josh’s death.

They’re hoping their story sparks a conversation and inspires the community and individual families to look at heroin head on.

“It could be learning disorders, mood disorders, just the difficulty of teen years. It’s a complicated thing to get through. We want people to understand that so they can manage their family and friends as best as possible,” Rick said.

“There’s a lot of people that don’t want to talk about bad stuff in their family, but it needs to be talked about in the community,” Joyce said.